JPS587313Y2 - Thermocut pull for gas safety device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a thermocouple for a gas headlight safety device.

In general, this kind of conventional thermocouple for a fire safety device, as shown in FIG. A rod-shaped thermoelement 2 made of alumel and a constant welded to the tip of the tubular thermoelement 1, and a thermocouple made of a conductive material whose one end is fixed to the other end of the tubular thermoelement 1 by brazing or the like. A mounting piece 3, a lead copper wire 4 whose one end is connected to the other end of the thermocouple mounting piece 3 by brazing or the like, and whose other end is connected to the solenoid valve body frame (not shown), and a rod-shaped thermoelement 2 whose one end is connected to the solenoid valve body frame (not shown). and a lead copper wire 5 connected to the other end of the electromagnetic coil, the other end of which is insulated from the solenoid valve body frame (not shown) and whose one end is connected to a proper position on the solenoid valve body frame. It was configured.

Then, the tip of the thermocouple configured as above was attached to 6
When the thermocouple is heated to about 00°C and then allowed to cool naturally in the atmosphere at about 25°C, the electromotive force of the thermocouple exhibits the characteristics shown in Figure 2, and the electromotive force reaches about 60°C until it reaches O. The cooling characteristics were not good, such as requiring a time of about seconds.

The reason for this is that the temperature difference between the hot junction, which is the weld between the tubular thermoelement 1 and the rod-shaped thermoelement 2, and the cold junction, which is the connection between the rod-shaped thermoelement 2 and the lead copper wire 5, does not easily reach O. was there.

Therefore, various improved structures can be considered in order to increase the cooling rate. For example, the cooling rate can be increased by changing the shape of the tubular thermoelement 1, but in this case, the life of the tubular thermoelement 1 may be adversely affected. There is a problem with putting it away.

Therefore, as another improvement plan, as shown in FIG. 3A, a rod-shaped element 6 made of the same material as the tubular thermo-element 1 is interposed between the rod-shaped thermo-element 2 and the lead copper wire 5 by brazing or the like. As shown in FIG. 3B, a structure has been considered in which the rod-shaped element 6 is connected to the rod-shaped thermoelement 2 by brazing or the like instead of the lead copper wire 5 and drawn out.

In all of these cases, a reverse voltage is generated due to the temperature difference between both ends of the rod-like element 6, so the characteristic curve of the electromotive force is the characteristic curve a for elements 1 and 2 and the characteristic curve a for elements 2 and 6, as shown in FIG. A characteristic curve C is obtained by combining the characteristic curves 1 and 2, and the cooling time is significantly shortened and the cooling characteristics are improved compared to the conventional example.

However, in the case of both sides, the material of the rod-like element 6 has a much higher specific resistance value than copper wire of the same wire diameter, so the internal resistance value of the thermocouple increases, and when combined with a solenoid valve, the necessary circuit current is reduced. It may not be possible to secure it.

Furthermore, if the wire diameter of the rod-shaped element 6 is increased in order to lower its resistance value, there is a risk that the material cost will increase or that the conventional set screw may no longer be usable.

Furthermore, in the example shown in FIG. 3B in particular, when attempting to connect the lead-out end of the rod-shaped element 6 to one end of an electromagnetic coil (not shown), there was a problem that soldering was not successful due to the properties of the material.

The present invention aims to provide a thermocouple for a gas headlight safety device that has excellent electromotive force characteristics such as the examples shown in A and B of FIG. 3, and eliminates the drawbacks and problems thereof. , one embodiment thereof will be explained based on FIGS. 3 to 5.

The basic structure and electromotive force characteristics of this embodiment are as shown in FIGS. 3 and 4, so their explanation will be omitted.

However, in the case of this embodiment, a lead wire cable 7 as shown in FIG. 5 is used instead of the rod-like element 6.

That is, this lead wire cable 7 is made of a core material 7a that generates a positive thermoelectromotive force with respect to the rod-shaped thermoelement 2 and whose value is larger than that of copper (gives a positive temperature difference), such as chromel, Inconel, iron, etc. are used, and a copper coating 7b is applied coaxially on the core material 7a, and an electrically insulating coating 7c of glass wool, resin, etc. is further applied thereon.

Therefore, according to this embodiment, the core material 7a of the lead wire cable 7 generates a reverse voltage as shown in FIG. 4 to improve the composite cooling characteristic, and the copper coating 7b increases the internal resistance value of the thermocouple. It is possible to secure the necessary circuit current for the solenoid valve by holding down the current.

Further, since the lead wire cable 7 is coated with a copper coating 7b, connection work such as soldering can be easily performed.

Furthermore, since the lead wire cable 7 has the core material 7a and the copper sheath 7b coaxial, it is excellent in mass production, and the electrically insulating sheath 7c can also be made in the same way as a normal cable.

As described above, in the thermocouple for a gas headlight safety device according to the present invention, a positive thermoelectromotive force is generated at the cold contact side end of the rod-shaped thermoelement, and its value is higher than that of copper. Since it is made by coaxially connecting a copper-coated lead wire cable to a large core material, it not only has good cooling characteristics but also has low internal resistance and secures the circuit current necessary for the solenoid valve. I can do it.

Furthermore, the connection with other members is good, and there is no increase in material costs or the loss of use of conventional parts.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional thermocouple for a gas headlight safety device, Figure 2 is a diagram showing the electromotive force characteristics of the above-mentioned conventional example, and Figure 3 is an example and basics of the thermocouple for a gas headlight safety device according to the present invention. 4th cross-sectional view of an improved version having the same structure
This figure shows the electromotive force characteristics of the improved type, and FIG. 5 is a perspective view of the lead wire cable used in the above embodiment. 1... Tubular thermoelement, 2...
Rod-shaped thermoelement, 3...Thermocouple mounting piece, 4゜5...Lead copper wire, 7...
・Lead wire cable, 7a...Core material, 7b...
...Copper coating.

Claims (1)

[Scope of utility model registration request] In a thermocouple for a thermocouple-type gas headlight safety device, one of a pair of thermoelements generates a negative thermoelectromotive force on the cold junction side of the other thermoelement, and a positive thermoelectromotive force is generated with respect to the other thermoelement. A thermocouple for a gas starter safety device is characterized in that a lead wire cable coated with copper is coaxially connected to a core material whose value is larger than that of copper even if the value is greater than that of copper.